Lever connector

ABSTRACT

Protrusions 35 are formed on cam grooves 33 of arm 32 of a lever 30 for the purpose of holding connector housings 10 and 20 in a preliminary fitted state. Engagement pins 12 are prevented from disconnecting from the respective cam grooves 33 when the female connector housing 10 is inserted slightly into a hood 21 of the male connector housing 20 such that he connector housings 10 and 20 are held in the preliminary fitted state. Accordingly, the lever 30 can be turned smoothly. Since no hole communicating between the interior and the exterior of the connector is formed in the inner part of the hood 21, there is no possibility that water may penetrate into the hood 21.

TECHNICAL FIELD

The present invention relates to lever connectors in which two connectorhousings are fitted to each other by turning a lever thereof.

BACKGROUND ART

FIG. 6 illustrates a conventional lever connector. Of two connectorhousings 50 and 60 fitted to each other, a female connector housing 50has two engagement pins 51 projecting from respective opposite sidewalls. The male connector housing 60 has two support shafts 61 formed onrespective opposite side walls thereof and a lever 62 whose arms 63extend from both ends of the lever and are rotatably mounted on thesupport shafts 61.

In connecting the connector housings 50 and 60 together, the femaleconnector housing 50 is inserted slightly into a hood 64 of the maleconnector housing 60 so that engagement pins 51 enter openings ofrespective cam grooves 65 formed in the arms 63. With insertion of thefemale connector housing 50 into the hood 64, a protrusion 52 formed onthe underside of the female connector housing 50 and a protrusion 66formed on the bottom of the hood 64 of the male connector housing 60move over each other, 25 thereby being engaged with each other. As aresult of the engagement of the protrusions 52 and 66, each of theconnector housings 50 and 60 is prevented from being moved in adirection in which they come apart from each other. Thus, both connectorhousings 50 and 60 are held in a preliminary fitted state wherein theengagement pins 51 are located in the respective cam grooves 65, asshown in FIG. 7.

Subsequently, the lever 62 is turned in the above-described state. Bothconnector housings 50 and 60 are held in the preliminary fitted statesuch that there is no possibility of disengagement of the engagementpins 51 from the respective cam grooves 65. Accordingly, the lever 62can be turned smoothly and reliably. By engagement of the pins 51 withthe respective cam grooves 65 caused by the turning of the lever 62, thefemale and male connector housings 50 and 60 are drawn nearer to eachother, whereupon both connector housings are connected together in afinal fitted state.

As described above, the conventional lever connector employs, as a meansfor holding both connector housings in preliminary fitted state, amethod of engaging the protrusion 52 formed on the underside of thefemale connector housing 50 and the protrusion 66 formed on the bottomof the hood 64 of the male connector housing 60 with each other.

However, this preliminary engaging means has the following problem. Thatis, a metal mold for forming a bottom face lying at the rear of theprotrusion 66 needs to be drawn out when the protrusion 66 is formed onthe bottom of the hood 64 of the male connector housing 60. Accordingly,a mold drawing hole 67 open to the outside of the hood 64 is formed inthe inner end face of the hood 64. Consequently, the interior of theconnector communicates with the exterior thereof through the hole 67 inthe state where both connector housings 50 and 60 are in fittingengagement. There is thus a possibility that water may penetrate intothe connector to thereby wet the terminals therein.

Another prior art lever connector will be described with reference toFIG. 16.

Of two connector housings fitted to each other, the male connectorhousing 170 has two support shafts 171 formed on opposite side wallsthereof, respectively, and a lever 172 which is formed into a U-shapeand which has plate-shaped arms 173 extending from both ends thereof androtatably mounted on the support shafts 171 in the same manner as in theforegoing prior art lever connector. The female connector housing hastwo engagement pins formed on opposite side walls thereof and engagedwith cam groove 174 formed in the inner side, faces of the arms,respectively. In the connection of both connector housings, the femaleconnector housing is slightly inserted into the hood 175 of the maleconnector housing 170 so that the engagement pins enter openings of camgrooves 174 of the arms 173, respectively. Upon turning of the lever 172in this state, the female connector housing and the male connectorhousing 170 are drawn nearer to each other by the engagement of theengagement pins with the respective cam grooves 174 caused by theturning of the lever 172, thereby being connected together.

In the above-described lever connector, an excessively large torque isapplied to each arm 173 when the lever 172 is turned. Accordingly, thearms 173 tend to be flexed outwardly such that the engagement pins aredisengaged from the cam grooves 174, respectively. If the arms 173should be flexed outwardly, they would be disconnected from therespective support shafts 171. In view of the this problem, falling-offpreventing walls 176 are provided on the outer side faces of the maleconnector housing 170 for preventing the arms 173 from being flexed andfalling off of the support shafts 171.

Each conventional falling-off preventing wall 176 has a portionextending outwardly from the side wall of the male connector housing 170in the shape of a plate, the portion being bent so as to face the outerface of the arm 171, as shown in FIG. 7. When the arm 173 is flexedoutwardly, the inner face of the falling-off preventing wall 176 iscaused to abut against the outer face of the arm 173, thereby preventingthe arm 173 from being flexed outwardly and consequently preventing thefalling-off of the arm 173 from the support shaft 171.

However, each falling-off preventing wall 176 is located outside the arm173. This increases the width of the male connector housing 170.Consequently, the connector cannot be mounted, or the mounting work isrendered difficult when a mounting space for the connector is small, orwhen there is some limitation in the mounting location or direction ofthe connector. This problem occurs in the case where the lever ismounted on the female connector housing as well as on the male connectorhousing.

SUMMARY OF THE INVENTION

The present invention has been made in view of the foregoingcircumstances. An object thereof is to provide a lever connector withpreliminary fitting means which can exclude the possibility of thepenetration of water into the 10 inner part of the hood of the maleconnector housing.

As a means for solving the above-described problem, the presentinvention provides a lever connector wherein a female connector housingis fitted into a hood of a male connector housing and both connectorhousings are held in a preliminary fitted state by inserting anengagement pin provided on one connector housing into a cam groove of alever mounted on the other connector housing so that the engagement pinassumes a preliminary fitting position. Both connector housings arefitted into a final fitted state by engagement of the engagement pinwith the cam groove upon turning of the lever. The cam groove is formedwith a protrusion allowing the engagement pin to be inserted into thecam groove so that the engagement pin assumes the preliminary fittingposition and prevents the engagement pin from falling out of thepreliminary fitting position outside the cam groove.

In connection of both connector housing, when the female connector isinserted slightly into the hood of the male connector housing, theengagement pin enters the cam groove of the lever, passing theprotrusion and assuming the preliminary fitting position. In this state,the engagement pin assuming the preliminary fitting position isprevented from being disconnected from the cam groove by the protrusion,whereby both connector housings are held in the preliminary fittedstate.

Upon operation of the lever in the preliminary fitted state, the leveris smoothly turned because there is no possibility of disengagement ofthe engagement pin from the cam groove. The female and male connectorhousings are drawn nearer to each other by the engagement of theengagement pin with the cam groove caused by the turning of the lever,thereby being connected into a final fitted state.

As described above, the protrusion is formed in the cam groove of thelever as a means for holding both connector housings in the preliminaryfitted state, and the engagement pin is engaged with the protrusion.Accordingly, a mold drawing hole need not be formed in the hood,although it is required in the prior art, where the protrusion isprovided in the hood of the male connector housing. Consequently, thewaterproofing in the hood can be improved.

The present invention further provides a lever connector wherein anengagement pin is formed on one of two connector housings and a lever isheld on the other connector housing and is engaged with the engagementpin to draw the same near thereto so that both connector housings arefitted. The one connector housing has a hood into which the otherconnector housing is inserted. Each of the lever and the engagement pinis provided with an engagement mechanism so as to be engaged with eachother in a manner of a concavo-convex engagement.

More specifically, the engagement mechanism is formed on the lever andthe engagement pin, which are engaged with each other. Without aspecific protrusion formed in the hood, the engagement pin and the leverare engaged with each other in the manner of a concavo-convex engagementin the preliminary fitted state, whereby the connector housings are heldin the preliminary fitted state.

Consequently, a mold drawing hole provided in the prior art need not beformed in the hood, and accordingly the waterproofing in the hood can beimproved.

The present invention further provides a lever connector with a leverthat has a cam groove which is formed around an axis of rotation thereofand into which the engagement pin is insertable. The cam groove has oneof two ends open at an end of the lever and approaches the rotation axisas the same extends toward the other end thereof. A protrusion is formedin the vicinity of the open end of the cam groove, the protrusionengaging the engagement pin in concavo-convex engagement.

Since the protrusion is provided in the groove into which the engagementpin is inserted, the engagement pin gets over the protrusion wheninserted into the cam groove so that both connector housings arepreliminarily fitted with each other. After having gotten over theprotrusion, the engagement pin is prevented from going backward and isheld in position.

The present invention further provides a lever connector where theprotrusion is formed on a side wall of the cam groove so as to abutagainst a side surface of the engagement pin, thereby engaging the same.

Since the protrusion is formed so as to abut against the side face ofthe engagement pin, the protrusion reliably abuts against the engagementpin even when the lever and the engagement pin are axially displaced.Consequently, the connector housings can be readily held in thepreliminary fitted state.

In further view of the above-described problems, the present inventionprovides a lever connector in which the arms of a lever can be preventedfrom being flexed outwardly and falling off of respective shafts withoutan increase in the width of the connector housing.

In a first lever connector, arms formed to extend from both ends of alever are rotatably mounted on support shafts projecting from oppositeside walls of one of two connector housing connected together.Engagement pins project from opposite side walls of the other connectorhousing and engage cam grooves formed on respective inner faces of thearms. Both connector housings are drawn nearer to each other to therebybe connected together by the engagement of the engagement pins withrespective cam grooves caused by the turning of the lever. The firstlever connector is characterized in that the falling-off preventingengagement portions are formed on the outer peripheral faces of the armsso as to be located inside the outer faces of the respective arms, thatfalling-off preventing walls are formed on the respective outer sidefaces of the one connector housing, each wall having a wall surfacelocated slightly outside the outer side face of each falling-offpreventing engagement portion, and that the arms are prevented fromfalling off from the support shafts by engagement of the falling-offpreventing engagement portions with the respective falling-offpreventing walls.

A second lever connector is characterized in that each falling-offpreventing engagement portion is formed to project in the shape of aplate inside the outer side face of each arm in the first leverconnector.

The third lever connector is characterized in that each falling-offpreventing engagement portion is formed by cutting the outer peripheralface of each arm in the shape of groove.

In a first lever connector, the falling-off of the arms from therespective support shafts is prevented by the engagement of theengagement portions with the respective walls even when each arm isflexed outwardly so as to deform in the direction of its disconnectionfrom the support shaft.

Each engagement portion is formed to be located inside the outer sideface of each arm. Moreover, an amount of outward displacement of thewall surface of each falling-off preventing wall is small relative tothe outer side face of each engagement portion. Accordingly, eachfalling-off preventing wall is not projected outwardly relative to thearm to a large extent.

In the second lever connector, the inner side face of the falling-offpreventing wall abuts against the outer side face of each plate-shapedengagement portion, whereby each arm is prevented from being flexedoutwardly and disconnected from the support shaft.

In the third lever connector, each falling-off preventing wall isinserted in he groove-like engagement portion. Each arm is preventedfrom being flexed outwardly and falling off from the support shaft bythe engagement of the inner face of the engagement portion with thefalling-off preventing wall.

In the above-described lever connector, the falling-off preventingengagement portions are located inside the outer faces of the respectivearms and the falling-off preventing walls are located slightly outsidethe outer side faces of the falling-off preventing engagement portions.Consequently, since the falling-off preventing walls are not projectedoutwardly relative to the respective arms to a large extent, the widthof the connector housing to which the lever is attached can be renderedas small as possible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an overall construction of a leverconnector of a first embodiment in accordance with the presentinvention;

FIGS. 2 and 2a are side views of the lever connector with connectorhousings in an unfitted state;

FIG. 3 is a partially cut-out side view of the lever connector with theconnector housings in a preliminary fitted state;

FIG. 4 is a partially enlarged and cut-out side view of the connectorwith the connector housings in the preliminary fitted state;

FIG. 5 is a side view of the connector with the connector housings in afinal fitted state;

FIG. 6 is a partially cut-out side view of a prior art lever connectorwith the connector housings in an unfitted state;

FIG. 7 is a partially cut-out side view of the prior art lever connectorwith the connector housings in a preliminary fitted state;

FIG. 8 is a perspective view of an overall construction of a leverconnector of a second embodiment in accordance with the presentinvention;

FIG. 9 is a perspective view of a lever employed in the lever connectorof the second embodiment;

FIG. 10 is a side view of the lever connector with the female and maleconnector housings in the fitted state;

FIG. 11 is a front view of a failing-off preventing mechanism of thelever;

FIG. 12 is a perspective view of an overall construction of a leverconnector of a third embodiment in accordance with the presentinvention;

FIG. 13 is a perspective view of a lever employed in the lever connectorof the third embodiment;

FIG. 14 is a side view of the lever connector of the third embodimentwith the female and male connector housings in the fitted state;

FIG. 15 is a front view of a falling-off preventing mechanism of thelever in the third embodiment;

FIG. 16 is a perspective view of a male connector housing of anotherprior art lever connector; and

FIG. 17 is a front view of a falling-off preventing mechanism of thelever in another prior art lever connector.

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment

A first embodiment in accordance with the present invention will bedescribed with reference to FIGS. 1 to 5. Referring to FIG. 1, anoverall construction of a lever 10 connector is shown. The leverconnector comprises a female connector housing 10 and a male connectorhousing 20 having a hood 21 into which the female connector housing 10is inserted. Terminals (not shown) are accommodated in cavities 11formed in the female connector housing 10. Other terminals are alsoaccommodated in cavities (not shown) formed in the male connectorhousing 20. The terminals in the female and male connector housings 10and 20 are electrically connected together when the female and maleconnector housings 10 and 20 are fitted together by a fitting mechanism,which will be described later.

The fitting mechanism fitting both connector housings 10 and 20 togetherwill be described. Coaxial engagement pins 12 having ends and sidesurfaces project from respective opposite side walls of the femaleconnector housing 10. Coaxial support shafts 22 project from oppositeside walls of the male connector housing 20. A generally U-shaped lever30 formed of a synthetic resin includes a lever base 31 and twoplate-shaped arms 32 extending from respective ends of the lever base31. The arms 32 of the lever 30 are rotatably mounted on the supportshafts 22. Each arm 32 of the lever 30 has a cam groove 33 formed on aninner side face thereof, each cam groove having a bottom and side wallsas illustrated. The engagement pins 12 of the female connector housing10 are engaged with the respective cam grooves 33. Each cam groove 33 isopen to the outer peripheral surface of each arm 32.

The hood 21 of the male connector housing 20 has escape grooves 24formed for allowing the engagement pins 12 to project outwardly of thehood 31 so that interaction between the hood 21 and the engagement pins12 is avoided when the female connector housing 10 has been inserted inthe hood 21. Each arm 32 of the lever 30 has two protrusions 35 locatedslightly inward from the opening of the cam groove 33. The protrusions35 protrude from opposite inner faces of each arm 32 toward each other.Each protrusion 35 has a triangular shape and has inclined faces at theopening side and inward side of each respective cam groove 33. A spacebetween distal ends of the protrusions 35 of each arm 32 is set to beslightly smaller than an outer diameter of each engagement pin 12.Provision of both protrusions 35 of each arm 32 has only one function,i.e. preventing each engagement pin 12 from returning or moving backwardafter each engagement pin 12 has been inserted into the cam groove 33.Accordingly, even when only one protrusion 35 is formed on either innerface of each arm 32, a concavo-convex mechanism can be constituted bythe engagement pin 12 and the protrusion 35. Furthermore, theconcavo-convex mechanism can be constituted even when the protrusion 35is formed on the bottom face of each cam groove 33. In this regard, thearms 32 are flexed outwardly when the engagement pins 12 have beeninserted in the respective can grooves 33. Additionally, a convexity maybe formed at each engagement pin side and a concavity allowing insertionof the convexity thereinto may be formed so as to be located slightlyinward from the opening of each cam groove 33.

The operation of the lever connector of the embodiment will bedescribed. In fitting both connector housings 10 and 20 together, thelever 30 is first put into a state such that the opening of each camgroove 33 is superimposed on the escape groove 24, as shown in FIG. 2.In this state, the female connector housing 10 is slightly inserted intothe hood 21. With this insertion, each engagement pin 12 advancesinwardly through the opening of the cam groove 33, elastically deformingthe arm 32 so that the cam groove 33 is spread, and passed through thespace between the protrusions 35. Thus, each engagement pin 12 reaches apreliminary fitting position, and both connector housings 10 and 20 areput into a preliminary fitted state as shown in FIG. 3.

Since the engagement pins 12 are engaged with the protrusions 35 of therespective cam grooves 33 in the preliminary fitted state, theengagement pins 12 are prevented from coming apart from the respectivecam grooves 33, whereby the connector housings 10 and 20 are held in thepreliminary fitted state.

Upon turning of the lever 30 in the preliminary fitted state, bothconnector housings 10 and 20 are drawn nearer to each other by theengagement of the engagement pins 12 with the respective cam grooves 33caused by the turning of the lever 30. The connector housings 10 and 20are put into a final fitted state in which the female connector housing10 has been inserted deep into the hood 21, whereby the terminals inboth connector housings are electrically connected together.

When turning of the lever 30 is initiated in the preliminary fittedstate, the engagement pins 12 are engaged with the protrusions 35 suchthat the engagement pins 12 are prevented from coming out of the camgrooves 33. Accordingly, the engagement of the engagement pins 12 withthe respective cam grooves 33 is initiated without trouble upon turningof the lever 30 so that the lever 30 can be operated smoothly andreliably.

As described above, in the embodiment, the protrusions 35 are formed inthe respective cam grooves 33 of the lever 30 as a means for holdingboth connector housings 10 and 20 in the preliminary fitted state, andthe engagement pins 12 are engaged with the respective protrusions 35.In the conventional method, the protrusions formed on the underside ofthe female connector housing and in the hood of the male connectorhousing are engaged with each other so that the connector housings areheld in the preliminary fitted state. Unlike the conventional method, amold drawing hole need not be formed in the inner part of the hood.Consequently, since no hole communicating between the interior and theexterior of the connector is formed in the inner part of the hood 21,there is no possibility that water may penetrate into the hood 21.

The present invention should not be limited to the above-describedembodiment and may be modified in practice as follows.

(1) The lever may be mounted on the male connector housing and theengagement pins are formed on the female connector housing in theforegoing embodiment. However, the lever may be mounted on the femaleconnector housing and the engagement pins may be formed on the maleconnector housing. See for example FIG. 2a.

(2) The protrusions holding the connector housings in the preliminaryfitted state can be formed on the inner faces of each cam groove in theforegoing embodiment. The protrusion constituting the feature of thepresent invention should not be limited to those formed on both innerfaces of the cam groove but may include ones formed on either one of theinner faces of the cam groove.

Otherwise, the present invention should not be limited to the embodimentdescribed above with reference to the drawings, and may be modified inpractice without departing from the scope of the appended claims.

Second Embodiment

FIGS. 8 to 11 illustrate a second embodiment. Referring to FIG. 8, anoverall construction of a lever connector is shown. The lever connectorcomprises a female connector housing 110 and a male connector housing120 having a hood 121 into which the female connector is inserted.Terminals (not shown) are disposed in respective cavities 111 defined inthe female connector housing 110. Terminals are also disposed inrespective cavities (not shown) defined in the male connector housing120. The terminals in the respective connector housings 110 and 120 areelectrically connected together when the female and male connectorhousings 110 and 120 are fitted by means which will be described later.

An elastically deformable lever 130 formed from a resin is mounted tothe male connector housing 120. The lever 130 includes a lever base 131and two plate-shaped arms projecting from ends of the base 131 and isformed generally into a U-shape. Describing the mounting structure forthe lever 130, the arms 132 are elastically deformed so as to spread.Two support shafts 122 projecting from opposite side walls of the maleconnector housing 120 are fitted into bearing holes 135 approximatelycentrally formed in the arms 132 so that the lever 130 is rotatablymounted on the male connector housing 120. Since the arms 132 of thelever 130 are loosely fitted in the respective bearing holes 135, thearms 132 are movable outwardly relative to the respective support shafts122.

A cam groove 133 is formed on the inner side face of each arm 132 of thelever 130 so as to be open at the outer peripheral face of the arm 132.Engagement pins 112 coaxially projecting from both outer side faces ofthe female connector housing 110 are engaged with the cam grooves 133,respectively.

In fitting both connector housings 110 and 120, the female connectorhousing 110 is inserted slightly into a hood 121 of the male connectorhousing 120 so that the engagement pins 112 are inserted into openingsof the cam grooves 133. Upon turning of the lever 130 in this state,both connector housings 110 and 120 are drawn nearer to each other bythe engagement of the engagement pins 112 with the respective camgrooves 133, whereby the female connector housing 110 is fitted deepinto the hood 121 such that the terminals in both connector housings areelectrically connected together.

An excessively large torque is applied to each arm 132 when the lever130 is turned. Accordingly, the arms 132 tend to be flexed outwardlysuch that the engagement pins 112 are disengaged from the cam grooves133. If the arms 132 should be flexed outwardly, they would fall offfrom the respective support shafts 122. In view of this problem, themale connector housing 120 is provided with means for preventing therespective arms 132 from being flexed and falling off from the supportshafts 122. The construction of the means will be described as follows.

Falling-off preventing walls 125 are formed on both outer side faces ofthe male connector housing 120 to be parallel to the respective arms132. Each all 125 has an arc-shaped portion 126 along a locus of adistal edge of the arm 132 in the case where the lever 130 is turned sothat connector housings 110 and 120 are fitted together. An inner wallsurface 127 of each wall 125 is located approximately midway of thethickness of the arm 132 and an outer wall surface 128 thereof islocated slightly inside the outer side face of the arm 132.

A plate-shaped falling-off preventing engagement portion 136 is formedon the outer peripheral face of each arm 132 at its distal end side soas to be parallel to the arm 132. A portion of each engagement portion136 corresponding to the opening of the cam groove 133 is cut out suchthat each engagement portion 136 is divided into two sections. An innerface 137 of each engagement portion 136 is planar with the inner face ofeach arm 132. An outer engagement face 138 of each engagement portion136 is located approximately midway of the thickness of each arm 132.The engagement face 138 of each engagement portion 136 faces the innerwalls surface 127 of the wall 125 with a small space therebetween.

The operation of the lever connector of the embodiment will bedescribed. Each engagement portion 136 is positioned inside the wall 125with a small space therebetween when the lever 130 is turned to fit bothconnector housings 110 and 120 together. In this regard, when each arm132 is caused to flex outwardly, the outer engagement face 138 of eachengagement portion 136 is abutted against the inner wall surface 127 ofeach wall 125 when each arm 132 has been slightly flexed. Furtheroutward flexure of each arm 132 is prevented by the engagement of eachengagement portion 136 with the wall 125. Consequently, each arm 132 isprevented from falling off from the support shaft 122.

The outer wall surface 128 of each wall 125 preventing the falling-offof the arm 132 from the support shaft 122 is located inside the outerside face of the arm 132. Accordingly, each wall 125 does not justoutside the arm 132 and the width of the male connector housing 120 isrendered as small as possible.

Third Embodiment

FIGS. 12 to 15 illustrate a third embodiment of the invention. Referringto FIG. 12, an overall construction of a lever connector is shown. Thelever connector comprises a female connector housing 140 and a maleconnector housing 150 having a hood 151 into which the female connectorhousing 140 is fitted. Terminals (not shown) are disposed in cavities141 formed in the female connector housing 140. Terminals are alsodisposed in cavities (not shown) formed in the male connector housing150. The terminals in the respective connector housings 140 and 150 areelectrically connected together when the female and male connectorhousings 140 and 150 are fitted by means which will be described later.

An elastically deformable lever 160 formed from a resin is mounted tothe male connector housing 150. The lever 160 includes a lever base 161and two plate-shaped arms 162 projecting from respective ends of thebase 161 and is formed generally into a U-shape. Describing the mountingstructure for the lever 160, the arms 162 are elastically deformed so asto spread. Two support shafts 152 projecting from opposite side walls ofthe male connector housing 150 are fitted into bearing holes 165approximately centrally formed in the arms 162 so that the lever 160 isrotatably mounted on the male connector housing 150. Since the arms 162of the lever 160 are loosely fitted in the respective bearing holes 165,the arms 162 are movable outwardly relative to the respective supportshafts 152.

A cam groove 163 is formed on the inner side face of each arm 162 of thelever 160 so as to be open at the outer peripheral face of the arm 162.Engagement pins 142 coaxialy projecting from opposite side walls of thefemale connector housing 140 are engaged with the cam grooves 163,respectively.

In fitting both connector housings 140 and 150, the female connectorhousing 140 is inserted slightly into a hood 151 of the male connectorhousing 150 so that the engagement pins 142 enter respective openings ofthe cam grooves 163. Upon turning of the lever 160 in this state, bothconnector housings 140 and 150 are drawn nearer to each other by theengagement of the engagement pins 142 with the respective cam grooves163 caused by the turning of the lever 160, whereby the female connectorhousing 140 is fitted deep into the hood 151 such that the terminals,are electrically connected together.

An excessively large torque is applied to each arm 162 when the lever160 is turned. Accordingly, the arms 162 tend to be flexed outwardlysuch that the engagement pins 142 are disengaged from the cam grooves163. If the arms 162 should be flexed outwardly, they would fall offfrom the respective support shafts 152. In view of this problem, themale connector housing 150 is provided with means for preventing thearms 162 from being flexed and falling off from the support shafts 152.The construction of the means will be described as follows.

Falling-off preventing walls 155 are formed on both outer side faces ofthe male connector housing 150 to be parallel to the respective arms162. Each wall 155 has an parallel arc-shaped portion 156 which iscoaxial with a locus of a distal edge of the arm 162 in the case wherethe lever 130 is turned so that both connector housings 110 and 120 arefitted together, and has a diameter smaller than the locus. An innerwall surface 157 of each wall 155 is located approximately midway of thethickness of the arm 162 and an outer wall surface 158 thereof islocated slightly inside the outer side face of the arm 162.

A falling-off preventing engagement portion 166 is formed by cutting theouter peripheral face of each arm 162 at its distal end side into agroove. A portion of each engagement portion 166 corresponding to theopening of the cam groove 163 is cut out such that each engagementportion 166 is divided into two sections. An inner face 167 of eachengagement portion 166 faces the inner wall surface 157 of each wall 155with a small space therebetween. A small space is defined between anoutside inner face 168 of each engagement portion 166 and an outer wallsurface 158 of each wall 155.

The operation of the lever connector of the embodiment will bedescribed. By turning the lever 160 for the fitting of both connectorhousings 140 and 150, the falling-off preventing walls 155 are insertedinto the respective grooves of the engagement portions 166. In thisregard, when each arm 162 is caused to flex outwardly, the inside innerface 167 of each engagement portion 166 is abutted against the innerwall surface 157 of each wall 155 when each arm 162 has been slightlyflexed. Further outward flexure of each arm 162 is prevented by theengagement of each engagement portion 166 with the wall 155.Consequently, each arm 162 is prevented from being disconnected from thesupport shaft 152.

Each wall 155 preventing the falling-off of the arm 162 from the supportshaft 152 is located inside the outer side face of the arm 162 in theembodiment. Accordingly, each wall 155 does not just outside the arm 162and the width of the male connector housing 150 is rendered as small aspossible.

The lever connector of the present invention should not be limited tothe above-described embodiment, and may be modified in practice asfollows, for example. The lever is attached to the male connectorhousing and the engagement pins are provided on the female connectorhousing in the above-described embodiment. However, the lever may beattached to the female connector housing and the engagement pins may beformed on the male connector housing.

We claim:
 1. A lever connector comprising:a female connector housing; amale connector housing having a hood for receiving said female connectorhousing; an engagement pin on one of said female connector housing andsaid male connector housing, said engagement pin having an outerdiameter; a lever pivotally mounted on the other of said femaleconnector housing and said male connector housing, said lever having acam groove having a width for receiving said engagement pin therein, andsaid lever being pivotal between a first position in which said camgroove is positioned such that said engagement pin can be introducedinto said cam groove so as to assume a preliminary fitting position andsaid female connector housing can be introduced into said hood of saidmale connector housing, and a second position in which said engagementpin has been moved due to engagement by said cam groove into a finalfitted position and said female and male connector housings have beenmoved together into a final fitted state; and a protrusion positioned onsaid cam groove such that when said lever is in said first position andsaid engagement pin is in said preliminary fitting position, saidprotrusion prevents said engagement pin from coming out of saidpreliminary fitting position outside of said cam groove; wherein saidcam groove has an opening for receiving said engagement pin, and saidprotrusion is positioned on said cam groove such that it is spacedinwardly of said opening along said cam groove, said protrusion reducingthe width of said cam groove at said protrusion and adjacent to saidopening to a size smaller than said outer diameter of said engagementpin.
 2. The lever connector of claim 1, wherein said protrusioncomprises two protrusions extending toward each other from opposite sidewalls of said cam groove.
 3. The lever connector of claim 1, whereinsaid lever is arranged such that when said lever is in said firstposition, said engagement pin can be inserted into an open end of saidcam groove, into contact with said protrusion, and past said protrusioninto said preliminary fitting position, at the same time that saidfemale connector housing is introduced into said hood of said maleconnector housing, and such that when said lever is in said secondposition, said engagement pin has been moved by said cam groove fromsaid preliminary fitting position to a portion of said cam groove thatis further from said protrusion than said preliminary fitting position.4. The lever connector of claim 1, wherein said cam groove has one openend and another end remote from said open end, said preliminary fittingposition is between said open end and said another end, said protrusionis between said preliminary fitting position and said open end and saidfinal fitted position is closer to said another end than saidpreliminary fitting position.
 5. The lever connector of claim 1, whereinsaid protrusion on said cam groove defines a concavity and saidengagement pin defines a convexity for engagement with said concavity.6. The lever connector of claim 5, wherein said lever has an axis ofrotation, said cam groove has one end thereof open at an end of saidlever and another end distant from the one end, and said cam groovecomes closer to said axis of rotation of said lever as said cam groovecomes closer to the other end thereof, said protrusion being locatedadjacent to said one end of said cam groove.
 7. The lever connector ofclaim 6, wherein said engagement pin has a side surface, and saidprotrusion abuts said side surface of said engagement pin when saidprotrusion and said engagement pin contact each other.
 8. A leverconnector comprising:a female connector housing; a male connectorhousing having a hood for receiving said female connector housing; anengagement pin on one of said female connector housing and said maleconnector housing, said engagement pin having an outer diameter; a leverpivotally mounted on the other of said female connector housing and saidmale connector housing, said lever having a cam groove for receivingsaid engagement pin therein, and said lever being pivotal between afirst position in which said cam groove is positioned such that saidengagement pin can be introduced into said cam groove so as to assume apreliminary fitting position and said female connector housing can beintroduced into said hood of said male connector housing, and a secondposition in which said engagement pin has been moved from saidpreliminary fitting position due to engagement by said cam groove into afinal fitted position and said female and male connector housings havebeen moved together into a final fitted state; and means positioned onsaid cam groove which reduces a width of said cam groove at a positionadjacent to an opening of said cam groove to a size smaller than saidouter diameter of said engagement pin for, when said lever is in saidfirst position and said engagement pin is in said preliminary fittingposition, preventing said engagement pin from coming out of saidpreliminary fitting position to the outside of said cam groove.